anyone who have used ifixit battery? is it good

As soon as you open an iPhone, you immediately void Apple's warranty and make your iPhone unserviceable by Apple.

Instead, take your iPhone to an Apple Store or Authorized Apple Service Center and let them handle your repair.

I would also like to hear of reviews of iFixIt batteries. I'm considering them for my family's iPhones that are well beyond even the longest possible Apple warranty period, so the warranty is now irrelevant. But we'd like to keep them going as backup and accessory devices.

Do not buy a third-party battery until you review the replacement procedure and feel confident that you can perform the repair and accept the risks.. Or, find a reputable service that will replace the battery for you.

I've repaired and upgraded my own Macs for many years (before they were made essentially impossible to upgrade) and the iPhone battery replacements look doable to me. But I would not recommend them to someone who has never worked inside a device before, because the iPhone procedure looks trickier than working inside most older Macs.

because the iPhone procedure looks trickier than working inside most older Macs.

Truer words were never spoken.